1. Field of the Invention
The present invention relates to a printed circuit board (PCB), and a method of designing the PCB, which prevents an uneven plating thickness on the PCB.
2. General Background
Generally, a conventional fabrication method of a PCB includes etching a copper foil on a polymer layer, drilling holes, electroplating, and trimming, etc. A plurality of traces is left after etching the copper foil. The PCB acts as a conductive body for a plurality of electronic components, and the PCB has strength to act as a supporting body for the electronic components.
Referring to FIG. 3, a conventional PCB design often results in having a dense concentration of traces in some areas, and a sparse concentration in other areas and a plurality of vias is arranged unevenly therein. Therefore, during plating, more current passes through the area of dense traces, than through the area of sparse traces. Thus, an uneven plating thickness occurs on the PCB, that is, larger plating thickness occurs on the inner walls of the vias located in the area of dense traces, and lesser plating thickness occurs on the inner walls of the vias located in the area of sparse traces. The plating thickness of the inner walls of the vias must reach a certain standard in order to satisfy the requirement of conductivity of the vias. In the area of sparse traces, the plating thickness of the inner walls of the vias may not be thick enough or even worse, not plated. In this situation, the PCB may be useless.
What is needed, therefore, is a PCB and a method of designing the PCB, which prevents an uneven plating thickness on the PCB.